Circuit interrupting device



March 5, 1963 o. FRoLAND CIRCUIT INIERRUPIING DEVICE Filed June s. 1960 March 5, 1963 o. FROLAND CIRCUIT INTERRUPTING DEVICE Filed June 3. 1960 3 Sheets-S1166?I 2 JNVENTOR. H141/ @0144@ BY yf/Lw( WM vae/vir March 5, 1963 o. FROLAND 3,080,466

CIRCUIT INTERRUPTING DEVICE Filed June 3, 1960 l 3 Sheets-Sheet 3 3,0%,466 CERCUH INTERRUPTNG DEVICE iav Frolantl, Milwaukee, Wis., assigner to McGraw Edison Company, Milwaukee, Wis., a corporation oi Delaware Filed .lune 3, i960. Ser. No. 33,755 ll Claims. (Cl. 20G- 146) This invention relates to circuit interrupting devices and, more particularly, to load break disconnecting switches.

Load brealr disconnect switches generally comprise a disconnect switch having a circuit interruptor in parallel with its main disconnect contacts and which is adapted to interrupt the circuit after the switch has been opened. Providing a parallel circuit around the main disconnect contacts while they are opening, eliminates the tendency for an arc to be struck between the stationary contact jaw and the movable switch blade, should the switch be opened under load. rThe circuit interruptor usually com-I prises fixed and movable contacts disposed in arc extinguishing structure and means for separating said contacts after the disconnect switch has been opened.

It is an object of the invention to provide a load break disconnect switch which cannot be accidentally or inadvertently opened without moving its operating lever from one extreme position to another.

lt is another object of the invention to provide a load break disconnect switch wherein the circuit interruptor cannot be reclosed until after the main switch contacts are closed so that said circuit interrupter is not required to carry heavy inrush currents,

A further object is to provide a load break disconnect switch with means for preventing the reopening of the disconnect contacts until after the circuit interruptor has been reset. 1

These and other objects and advantages of the invention will become more apparent from the detailed description of the invention taken with the accompanying drawings in which:

lFlG. i is a side elevational View, partly in section, of the load break disconnect switch according to the instan inventiony in its closed position;

FlG. 2 is a top plan View of the load break disconnect switch shown in PIG. l, with parts broken away;

-FlG. 3 is a front elevational view of the device with parts broken away;

FIG. 11.- is a rear elevational view of the preferred embodiment of the invention, with parts broken away;

`'FI-G. 5 is a View taken along lines 5 5 of FIG. 2;

IFIG. 6 is a side elevational view of the device with its main contacts and interrupting contacts open; and

FiG. 7 shows a partial side elevational View of the preierred embodiment of the invention and illustrates the operation of its safety latch mechanism.

Referring to the drawings in greater detail, the invention comprises, in general, the combination of an air disconnect switch designated generally by the reference numeral lll and a load interrupting device ll. The disconnect switch 1li includes switch blade means which comprises a pair of parallel switch blades l2 pivotally mounted on a pair of conductive frame members 14 which in turn are mounted atop a iirst porcelain bushing lo. A stationary contact jaw i8 is disposed atop a second porcelain bushing 2) and is engageable by the switch blades l2 when the latter are moved into their closed position.

Sddfidh Feten-.ted Mar. 1963 las? the arms 24 and the switch blade l2. Bearing pressure is provided between arms 2d and switch blades 12 by spring washers 28 which surround each hinge pin 26 and which are forced against the surface ot the outer arm 24 by nuts liti received on the threaded outer end ol' each hinge pin 26. ln this manner, good electrical contact is achieved between switch blades l?. and support arms 24 so that current interchange may be accomplished with a minimum of heating.

Each ot the frame members i4 is mounted on a conductive base plate E?, which may be connected to one of the incoming or outgoing line conductors (not shown). The stationary contact jaw 18 comprises pairs of parallel contact lingers 3d atlixed at their lower ends to a conductive base plate 56 which is adapted to be connected tothe other line conductor (not shown).

The circuit interrupter ll is located between switch blades l2 and includes a tubular housing ill having stationary contacts 41 disposed near its Contact jaw end and a movable contact rod 42 coaxially disposed for longitudinal movement relative to said stationary contacts.

The outer shell of the tubular 1'rousing dit is composed of any suitable insulating material such as Bakelite and its inner surface is composed oi an arc quenching gas evolving material 43, such as ber. A conductive end cap i6 is secured to one end of tube itl and carries the stationary contacts di and on its inner surface and a by-pass rod i7 coaxially aixed to its outer surface. The other end of tubular housing dil threadably receives a metallic guide bushing dit having axial bore i9 tor slidably receiving the movable contact d2.

Integral with the upper surface of guide bushing 4S is an inverted Ueheped mounting bracket Sit whose arms 5l are each rigidly secured to one of the switch blades l2. In this manner, the switch blades l2 and the circuit interruptor l1 are rigidly athxed for unitary pivotal movement as said switch blades are rotated between their opened and closed positions.

In addition, an elongate channel member 52 is affixed to the mounting bracket 5G and extends rearwardly theretrom. A longitudinal slot 53 is formed Yon each side of channel member 52 and each extends from the guide bushing 4S to a point slightly beyond pivotal axis of switch blades l2. v

Referring specifically now to FlG. 2, it can be seen that the end of the movable contact rod 42 threadedly engages a guide block 54 which has a recess 56 for receiving a coaxially disposed contact opening spring 58 that extends between an eye 5% in the end of movable contact rod d2 `and a cross pin dil extending between the opposite sides of channel member 52 near its hinge end. As seen in FIGS. 2 and 5, guide block 54 is mounted for sliding movement between the sides of channel member S2 by a pair of integr-al guide shoulders 62 which extend longitudinal-ly along the lateral sides of block 54 and which are disposed in slots 53. In a similar manner, an operating block 64, as shown in FIGS. 2 and 3, is also slidably mounted in slots 53 between guide block 54 and the hinge end of member 52 by guide shoulders 65 formed integrally on each lateral side thereof.

Disposed between each ofthe members 14 and the sides of channel member 52 is one of the vertical arms 68 of a U-shaped frame member 69. A second pair of parallel guide slots are formed in the enlarged upper ends of arms 68 and in a parallel relation to slots 53 and each extends from a point Iadjacent the operating block 64- to the pivotal axis of switch blades 12. Extending laterally from each shoulder 65 of operating block 64, through slots 53 and into slots 70 are a pair of transverse operating pins 72.

The movable contact 42 of circuit interruptor l1 is held in its closed position shown in FIGS. 1 and 2 -by a latch sgoa'aasc link 73 which is engageable with a latch 74 formed on a lower edge of operating block 54. Latch l-ink 73 is pivotally mounted -on a shaft 75 journalled between la pair of ear-s 76 Vdepending from each of the` lateral sides of cham nel 52. A torsion spring 77, which surrounds shaft 75,` urges rotation of latch linkl 73 ina counterclockwise direction. This rotation is limited' by a transverse pinV 78 extendingv laterally from latch arm 73 for engagement with oneioffthe lower edges of channel member 52.

An inverted,A U-shaped, operating handle 84 Ihaving a pullring 85 :anda pair of dependingrlegs 86 which are pivotally mounted -at their lower ends on atransverse shaft 88 extending between a bracket member S9 ailixed toeachfof theswitch blades l12. An -operating'linkA 90 is connected at one end to each of the dependingv legs 86y of operating handle 84 'and vat its other end to one of the transverse operating pins 72 projectingfrom operatingl block 64'.

From the descriptionthus far, it will be' appreciated thatwhen theassembly'is in kits closed position shown in FIGS. 1 yand 2, rotation of'swit'ch4 blades 12 would. tendk to move operating block 64m an -arc whose centerofY curvature" islocated at the pivotal axis-ofsaid switchblades.` Movement of'operating block 64 in this manner, however,` is prevented becauseof the engagement of operating pins-72 and: 'stationary slots 70.'l T-hus, when operating handle 84 is in its unrotated position, shown in FIGS. 1k and- 2, switch blades 12 are locked in position because operating pins 72 prevent relative; rotation between slots-53in channel member 52y and stationary slots 70.l

In order to release switch blades 12 for pivotal movement to their open position, operatingl handle 84 Vis rotated in a counterclockwise direction by a hook stick `or the like, moving operating block 64l through the; 4agency of operating rods 90 from its position in FIG. 1 to the left end of slots 70, as shown in FIG. 3. This places operating'pins 72 at the rotational axis ofswitch blades 12. Further rotation of operating handle 84 is prevented by apair of stop members 94 extending inwardly from each of Vthe'switch bl-ades 12 and lying in the path of its pivotal movement. It can be seen that when operating pins 72 are coaxial with the rotational axisk of switchf bladesA` 12 clot 53, carried 'by member 52, will be f ree to rotaterelative to fixed slot70 so that'switch bladef12y can move out'of engagement with contactv ingers 34;v Inv thism`anner', switch 10-is'locked inA a' closed position "until oper# ating handle 84 has been fully rotated 'thereby minmiz ingthe probability of accidental opening.

It will" be recalled that when the switch is 'in itscl'osed position,`as 1shown in` FIG; l, latch arm 73' engages 4latch 74 to hold movable contact vrod 42 in closed position'. Asithe circuit .interrupter 11 and the switch blades" 12 begin to' rotate in a' counterclockwise directionv from their closed positions; spring 77` holds pin 78`lagainst"th`e lower edge'sof channel member'52as it rotates.' so thatlatching members4 73 andv 74 will remainin` engagement andrmov# able contact 42 will remain latched." Current'will," there fore, continue to tlow through the' load interrupteralong alpath defined by`conductive base plat`e`36, stationary by.'- passcontacts 104,2 fixed and' movable contactsA 41. and42`, vthe current interchange springj'45, guide block 48,1the mounting 'bracket'50 and the switch blades"12. As a re'- sult, when the. main disconnectswitch is 'opened no' arc will be struck between stationary' contactngersil and switch`blades'12. After the switch blade 12has Cleared the stationary contact jaw 18, further rotation o-fthe switch Iblades 12A will bringY atrip pin 96"exten`din`g transversely 'from a'depending leg 98 'integral with latch arm 73 intov engagement with the .hookedend 100 of a trip lever 101 pivotally mounted betweenthe legs 68'of 'frame member 69 and urgedfor rotation in a counterclockwise direction by torsion spring 102. This prevents further rotational movement of latch armi'73, so that -as guide block l54 continues rotatingV with .interrupterv 11,. latch 74 will .move out of engagement with the now stationary latch arm 73 whereupon guide block 54 and contact rod 42 are free to move to the left as viewed in FIGS. l, 2 and 6 under the inuence of opening spring 58, whereby the circuit is interrupted. Y

After thecircuit interrupter has opened, continued rotation of the assembly will move by-p'ass rod 47 out of engagementwiththe stationary by-pass Ycontacts 104. It will be appreciated that when the switch 10 is in this open position slots53 and 70Av will be out of parallelism so that operating pins 72`^cannot be moved-out of alignment with the pivotal axisoffswitch blades 12. For this reason, the operating handle cannotfbe rotated in a Iclockwise direction to move the contact rod 42 into its closedl positionwhen the switch blades 12 are out of engagementwith contact jaw 18. This prevents damagiuginrush-` currents from flowing through interrupter 11 uponthe reclosing of switch 10.

Alsafety latch .assembly` 110, shown in FIGS. l, 4, 6 and 7, is provided toiprevent the reopening of the disconnect switch- 10( afterswitch blades 12 have been rotatedl from their openedj to their closed` position priorV tothe reclosureofcircuit interrupter 11. This assembly' includes a latch. member .112 pivotally mountedby means of-a pin 113'; extending-between apair of vertical frame members 1`15- .and biased-vfor-rotation inr a clockwise direction' by a torsion spring 120. Rotationalmovement of safety latch 112i's limited by a transverse pin 121 extending laterally fromoneside into an arcuate slot 123 formed in one of the frame portionsc114. When switch blades 12 arevin .theirA closed position, as shown in FIG. l, safetyV latchV 112r isl restrained withpin 121near the upper end of slot 123- byfa latch arm 124 ailixed to a shaft 125 pivotally mountedrbetween a pair of bracket members 126 secured to the base36. In addition, a trip arm 127 is also rigidly-.attached to shaft 125. A torsion sp`ring129-biases shaft 125 ina counterclockwise direc` tionfso that trip". arm 127 and. latch arm 124 are urged toward their positions shown in FIG. 1.

Upon rotationfof switch blades 12 and circuit interrupter 11` from: their position shown in FIG. l, shaft 88; willl engage the uppercndof trip arm 127 to rotate shaft 125 in a clockwise direction in opposition to ytorsion spring"129. This swings the end of'latch arm 124downwardly, thereby allowing safety latch 112" to rotate in a clockwise direction under the influence of spring 120; from-'its'position 'shownfin FIG. 1- until pin 121 engages the lower end'. of slot 123 as'sh'own' in FIGS. 6 and 7. When the switch" 10is thereafter reclosed, shaft 88' will move downwardly from its position shown in FIG, 6A to its positio'ht shownin FIG. 7 where `it will be engaged by safety'- latch-130.` This prevents switch'blade'lZ fron-'tbe'- ingjrotated out'ofengagement with stationary contact lingers 34.* However, whenoperating handle 84' is rotated in` af clockwise direction from itsv position shown inL` FIG. 7 to'the position shown in- FIG. 1,\a\cocking bar 132'extendingbetween legs 86, is moved into engagement with safety: latchE 112-to`- rotate it in a` counterclock Wise* direction luntil latchA lmember 112v re-enga'ges' latch armf124; Itcan? be seen, too,` however, that such rotattion of operating handle'84 moves operatingblock 64 and guide block 54 to theright through the'agency of operating links iuntil'latch' 74 re-engages latchv arm 73 whereupon the circuit'interrupter is againI latched in closed position.`

The safety: latch assembly` is then reset so that the switch` 10 may-again beopened in the manner described above.

From the foregoing it can be seen that slots 53 and 70 and operating block 64 cooperate to prevent the accidental opening of switch 11 prior to the rotation of operating handle. 85 from one extreme position to another. These members `also cooperate to prevent thel reclosure ofA circuit interrupter 1.1` prior tov-thereclosure of-switch blades 12. In addition,.safety latch' mechanism 110 prevents the opening of switch blades 10 when circuit interrupter 11 is open.

While only a single embodiment of the instant invention has been shown and described, other modifications will be apparent to those skilled in the art once the in ventive concept is known. Accordingly, it is intended to cover in the appended claims all such modiiications and variations which fall with the spirit of the invention.

I claim:

l. The combination of a load interrupting device and a disconnect switch, said disconnect switch including stationary'contact means and switch blade means rotatable into and out of engagement therewith, an operating handle rotatably mounted relative to said switch blade between rst and second positions, locking means connected to said switch blade and to said operating handle for preventing the rotation of said switch blade means to its open position until said operating handle has been rotated from its first to its second position, latch means for holding said circuit interruptor closed, means for tripping said latch means to open said circuit interrupter after said disconnect switch has been opened, said locking means also preventing the rotation of said operating handle from its second position to its tirst position after said switch blade means has been opened until the reclosurethereof, movement of said operating handle from said second to said iirst position after a reclosure of said disconnect switch being operative to relatch said circuit interruptor in closed position, and safety latch means for preventing thereopening of said disconnect switch after a reclosure thereof until said circuit interruptor has been latched closed.

2. A disconnect switch including stationary contact means and switch blade means pivotable into and out of engagement therewith, an operating handle pivotably mounted relative to said switch blade between tirst and second positions, locking means operatively associated with said switch blade and said operating handle for preventing the rotation of said switch blade means to its open position until said operating handle has been pivoted from its iirst to its second position, said locking means also preventing the rotation of said operating handle from its second position to its first position after said switch blade means has been opened until the reclosure thereof.

3. A disconnect switch having a pair of spaced apart terminals, switch blade means pivotally mounted on one of said terminals for engagement with the other, an operating handle movable relative to Said switch blade means between first and second positions, a locking member slidably engaging said switch blade means and said one terminal for movement between an initial and a inal pos1tion, said locking member being operative when in its initial position to prevent pivotal movement of said switch blade and inoperative to prevent such movement when in its 4final position, said operating member being connected to said operating handle for movement from its initial to its iinal position when said operating handle is moved from its lirst to its second position.

y4. A disconnect switch having a pair of spaced apart terminals, switch blade means pivotaliy mounted on one of said terminals for engagement with the other, an D- erating handle movable relative to said switch blade means between iirst and second positions, a locking member slidably engaging said switch blade means and said one terminal for movement to the pivotal axis of said switch blade from a point remote therefrom so that said switch blade is free for pivotal movement to its open position, said locking member being operative in all other positions to prevent such pivotal movement, said locking member being connected to said operating handle for movement to said pivotal axis when said operating handle is moved from its rst to its second position.

5. A disconnect switch having a pair of spaced apart terminals, switch blade means pivotally mounted on one of said terminals for engagement with the other, said switch blade means having a iirst guide means formed therein, said one terminal having a second guide means formed therein and disposed adjacent said rst guide means when said switch blade means is in its closed position, an operating handle pivotally mounted relative to said switch blade means between rst and second positions, .a locking member cooperatively engaging each of said guide means and movable therein between initial and iinal positions, said locking means being operative to prevent pivotal movement of said switch blade when in its initial position and inoperative to prevent such movement when in its final position, said operating member being connected to said operating handle for movement from its initial to its final position when said operating handle is moved from its iirst to its second position.

6. A disconnect switch having `a pair of spaced apart terminals, switch blade means pivotally mounted on one of said terminals for engagement with the other, said switch blade means having a rst longitudinal guide means formed therein, said one terminal having a second guide means formed therein adjacent said tirst guide means, said guide means being substantially parallel when said switch blade means is in its closed position, an operating handle pivotally mounted on said switch blade means between iirst and second positions, a locking member mounted on said switch blade means and cooperatively engaging each of said guide means for movement therein between an initial and a tlnal position, said locking member being operative to prevent pivotal movement of said switch blade when in its initial position and inoperative to prevent such movement when in its nal position, said operating member being connected to said operating handle for movement in said guide means from its initial to its iinal position when said operating handle is moved from its first to its second position.

7. A disconnect switch having a pair of spaced apart terminals, switch blade means pivotally mounted on one of said terminals for engagement with the other, said switch blade means having a iirst longitudinal slot formed therein and intersecting its pivotal axis, said one terminal having a second stationary slot formed therein and intersecting the pivotal axis of said switch blade means, said slots being substantially parallel when said switch blade means is in its closed position, an operating handle pivotally mounted relative to said switch blade means between lfirst and second positions, a locking member mounted on said switch blade means and engaging each of said slots, said locking member being connected to said operating handle for movement in said slots to the pivotal axis of said switch blade means from a point remote therefrom when said operating handle is moved from its iirst to its second position.

8. rThe combination of a load interrupting device and a disconnect switch, said disconnect switch including stationary contact means and switch blade means rotatable into and out of engagement therewith, actuating means for rotating said switch blade means between its openef and closed positions, latch means for holding said circuit interrupter closed, means for tripping said latch means to open said circuit interruptor after said disconnect switch has opened, said actuating means being operative to relatch said circuit interruptor after said disconnect switch has been reclosed, and safety latch means for preventing the reopening of said disconnect switch after a reclosure thereof until said circuit interruptor has been latched closed.

9. The combination of a load interrupting device and a disconnect switch, said disconnect switch including spaced terminals and switch blade means pivotably mounted on one terminal for engagement with the other, operating means mounted for movement relative to said switch blade means, said circuit interrupter lhaving separable contacts and latch means for holding said contacts in closed position, means for tripping said latch means to open said circuit interrupter after said disconnect switch has opened,` said operating means being connected to said interrupter contacts and movable between irst and second .positions to reclose the same after said disconnect switch has been closed, and safety means operable tov latch said switch blade means in closed position upon the reengagement thereof with said other terminal, said operating means also being operable to unlatch said safety means upon movement between its first and second positions, whereby said disconnect switch cannot be opened after its reclosure until said circuit interrupter has been latched closed.

10. The combination of a load interrupting device and a disconnect switch, said disconnect switch including spaced terminalsv and switch blade means pivotably mounted on one terminal for engagement with the other,

-operating means pivotably mounted 'on said switch blade .for Amovement relative thereto between iirst and second positions, said circuitinterrupter having lixed and movable vinterrupting contacts and latch means for holding Asaid movable contact in closed position, means for tripping said latch means to release said movable contact after said disconnect switch has been opened, said operating means being connected to said movable contact vand operable upon movement from its lirst to its second switch blade means upon movement between its first and second positions, whereby said disconnect switch means ,cannot be opened after a reclosure thereof until said circuit interrupter has beenrlatched closed.

l1. The combinationy of a load interrupting device and a disconnect switch, said disconnect switch including stationary contact means and switch blade means pivotable into and out of engagement therewith, an operating handle rotatably mounted relative to said Switch blade means between lfirst and second positions, locking means connected to said switch blade means and to said operating handle for preventing pivotal movement of said switch blade means to its open position until said operating handle has been rotated from its 'lirst to its second position, latch means for kholding said circuit interrupter closed, means for tripping said latch means to open said circuitinterrup-ter after said disconnect switch has been opened, said locking means also preventing the rotation of said operating handle from its second position to its kfirst position after said switch blade means has -been References Cited in the file of this patent UNITED STATES PATENTS Rathert Feb. ,22, 1949 Schneider t.- May l, 1956 

1. THE COMBINATION OF A LOAD INTERRUPTING DEVICE AND A DISCONNECT SWITCH, SAID DISCONNECT SWITCH INCLUDING STATIONARY CONTACT MEANS AND SWITCH BLADE MEANS ROTATABLE INTO AND OUT OF ENGAGEMENT THEREWITH, AN OPERATING HANDLE ROTATABLY MOUNTED RELATIVE TO SAID SWITCH BLADE BETWEEN FIRST AND SECOND POSITIONS, LOCKING MEANS CONNECTED TO SAID SWITCH BLADE AND TO SAID OPERATING HANDLE FOR PREVENTING THE ROTATION OF SAID SWITCH BLADE MEANS TO ITS OPEN POSITION UNTIL SAID OPERATING HANDLE HAS BEEN ROTATED FROM ITS FIRST TO ITS SECOND POSITION, LATCH MEANS FOR HOLDING SAID CIRCUIT INTERRUPTER CLOSED, MEANS FOR TRIPPING SAID LATCH MEANS TO OPEN SAID CIRCUIT INTERRUPTER AFTER SAID DISCONNECT SWITCH HAS BEEN OPENED, SAID LOCKING MEANS ALSO PREVENTING THE ROTATION OF SAID OPERATING HANDLE FROM ITS SECOND POSITION TO ITS FIRST POSITION AFTER SAID SWITCH BLADE MEANS HAS BEEN OPENED UNTIL THE RECLOSURE THEREOF, MOVEMENT OF SAID OPERATING HANDLE FROM SAID SECOND TO SAID FIRST POSITION AFTER A RECLOSURE OF SAID DISCONNECT SWITCH BEING OPERATIVE TO RELATCH SAID CIRCUIT INTERRUPTER IN CLOSED POSITION, AND SAFETY LATCH MEANS FOR PREVENTING THE REOPENING OF SAID DISCONNECT SWITCH AFTER A RECLOSURE THEREOF UNTIL SAID CIRCUIT INTERRUPTER HAS BEEN LATCHED CLOSED. 